Total energy calculations in the DFT on binary compounds

Abstract

Calculations are carried out using first-principles self-consistent local-density and nonlocal density theory of the electronic structure, the total energy, and the charge density of a variety of semiconducting and insulating compounds under hydrostatic and uniaxial pressure. For several cases, the transition pressure from one structure to another is determined as well as the pressure coefficients of the main band gaps. It is shown that several properties are calculated with adequate accuracy to be compared with experiment, so that values which have not yet been measured are trustworthy predictions. 0 1995

Seven-Fold Coordinated MgSe and 202GPa.

“…With this in mind a study of MgTe and MgSe was begun. It was found that at atmospheric pressure MgTe existed both as the wurzite and nickel arsenide structure and that the B8, NiAs, phase was the more stable, and persisted at high pressure [4], consistent with calculations [5,6]. In the ideal B8 phase of MgTe, the magnesium atom is surrounded by eight equidistant atoms, six tellurium atoms and two magnesium atoms , while the tellurium is surrounded by six equidistant atoms of magnesium.…”

Phase transition and thermodynamic properties of MgTe under high pressure

“…[18] microscopic point of view. The calculated equilibrium lattice constants a, elastic constants C ij , zero-pressure bulk modulus B 0 and its pressure derivation B 0 from the Birch-Murnaghan equation of state (EOS) [17] are listed in Table 1, together with other theoretical results [5][6][7][18][19][20][21][22][23][24][25][26][27]4] and the experimental data [28]. The agreements among them are good.…”

“…These calculations are therefore used to investigate the structures of materials at high pressures. The significant advances in computational materials science have made possible the use of ab initio quantum mechanical techniques to predict MgTe the electronic structure [3,6], the phase transition [4,5] and optical properties [7]. Such studies could play a significant role from the standpoint of predicting the performance of the material under extreme conditions.…”

“…With the wide-gap binary A N B 8−N semiconductors and promising potential of alkaline earth chalcogenides (AECs) used for various electrical and optical devices, MgTe has recently led to extensive studies in both theoretical [1][2][3][4][5][6][7] and experimental [8,9]. Recently, lots of properties of solids have become possible to compute with great accuracy from the first principles methods.…”

Phase transformation and elastic behavior of MgX (X=S, Se, Te) alkaline earth chalcogenides

“…The calculated values of SOECs, bulk modulus B T and tetragonal modulus C S are given in Table 4 and are also compared with others works [4,9,12,20,25,[27][28][29][30][31][32][33][34]. Vukcevich [35] proposed a high-pressure stability criterion for ionic crystals, combining mechanical stability with minimum energy conditions.…”